Process of preserving wood



Patented Sept. llll, 1&23.

RUJDGYARD I. SMITH, 015 WASHINGTON, DISTRICT OF COLUMBIA.

PROCESS 01F PRESERVING WOGD.

1T0 Drawing.

To all whom it may concern.

Be it known that I, RUDGYARD I. SMITH, a citizen of the United States, residing at Washington, in the District of Columbia, have invented'certain new and useful I mprovements in Processes of Preservi ng Wood, of which the following is a specification.

My invention has to do with the preservation of wood by the saturation or impregnation of the wood by certain chemicals. To this end I employ a process Which is not only economical in the material to be used and capable of being carried out with an 1nexpensive equipment, but produces results not attainable with processes heretofore employed.

Another object of my invention is to employ certain chemicals as above stated, which when used as hereinafter described, will cause a certain reaction to take place in the wood, which will result in the precipitation of an insoluble precipitate throughout the wood.

Heretofore it has been diflicult to get sufficient penetration for reasons that preservatives that are satisfactory as sterilizers will not enter freely into the pores of the Wood or throughly attack the active fermenting contents of the wood.

One feature of my invention, therefore, consists in treating the Wood, first with a solution that enters freely into the innermost pores of the wood, and then with a disinfecting agent which follows freely wherever the' first agent has penetrated, and the thoroughness of the process is thereb insured. For the first agent, I preferably select a solution of an antiseptic nature to assist in disinfecting the fermenting properties of the wood, and this first agent is preferably a solvent of the fermenting content.

Heretofore, for the sake of economy, so-

lutions of salts in Water have been employed for the purposes of preserving Wood, but

Application filed fieptember 19, 1922. Serial No. 589,232.

employ a solution of ordinary commercial copperas or iron sulphate for the first solution, and a solution of ordinary blue vitriol or copper sulphate combined with the ordinary commercial tannic acid for the subsequent treatment. I have found in practice that a solution of iron sulphate in the proportions of about one half pound of iron sulphate to one gallon of water, and the second solution one half pound of copper sulphate and one ounce of tannic acid to one gallon of Water will efiectively produce the desired results, if applied in accordance with my invention, viz., by first soaking the wood in the first solution for about 12 to 24 hours according to the character of the wood, and then soaking the wood thus saturated in the second solution from 12 to 24 hours. I have found by experiment that Wood thus treated will withstand decay, retains strength, resiliency and does not increase the weight of the wood. My process can be applied to either the seasoned or unseasoned wood with the same valuable results. While I know that a certain chemical reaction takes place in the Wood treated by my process, I have thus far been unable to find out just what this reaction is.

I claim The process of treating Wood for preserving it, which consists of first soaking it in a solution of sulphate of iron, and then subjecting it to a solution of sulphate of copper and tannic acid.

RUDGYARD I. SMITH. 

